Conclusion

The Canon EF-S 17-55mm f/2.8 IS USM is the fastest standard zoom dedicated to Canon's APS-C DSLRs, and is designed to be an upgrade for disgruntled kit lens owners who want better image quality. In many ways this 7-year old lens succeeds in its aim, although you need to stop-down to f/4 throughout the zoom range to acceptably sharp results.

The Canon EF-S 17-55mm f/2.8 IS USM is a well-built lens, although not in the same league as Canon's L-series lenses and perhaps not quite what we'd expect given the high price-tag. The capable 3-stop image stabilisation system used in conjunction with the latest generation of EOS bodies is a low-light shooter's dream ticket, making it easy to hand-hold the camera and still get the shot. Auto-focusing is quick, accurate and quiet thanks to the USM motor, although not as silent as lenses equipped with the newer STM motor. The ability to instantly manually override the AF system via the focus ring if required is a nice touch.

Image quality is good rather than outstanding. Centre and edge sharpness isn't great throughout the zoom range at the maximum aperture of f/2.8, but stopping-down by one stop sharpens things up considerably, whatever focal length you use. Chromatic aberrations are fairly well controlled, though, and there's only slight geometric distortion at the wider focal lengths and a little corner shading at the maximum aperture. The lens doesn't ship with a hood or a lens case/pouch, although the Super Spectra coatings successfully prevented contrast loss attributable to flare.

So despite its age, the Canon EF-S 17-55mm f/2.8 IS USM remains a good option for kit lens users looking to upgrade, or if you want the best dedicated standard zoom for your Canon APS-C camera and don't mind paying for the privilege.